Epictetus opens his handbook by cutting the world in two. Some things are up to us - our judgements, our intentions, what we go after and what we avoid - and everything else is not: the body, reputation, office, other people, how any of it turns out. Almost all Stoic advice is an application of that one division. The passages below work it from both ends. Some press the diagnosis, that we suffer by staking ourselves on things that were never ours to hold. Others take the other side of the bargain, arguing that whatever the universe hands you is to be met without complaint, because it comes from the same order that produced you.
— Epictetus, The Enchiridion 17"For this is your business, to play admirably the rôle assigned you; but the selection of that rôle is Another's."
— Epictetus, The Enchiridion 12"If you wish to make progress, dismiss all reasoning of this sort: "If I neglect my affairs, I shall have nothing to live on." "If I do not punish my slave-boy he will turn out bad." For it is better to die of hunger, but in a state of freedom from grief and fear, than to live in plenty, but troubled in mind."
— Epictetus, The Enchiridion 8"Do not seek to have everything that happens happen as you wish, but wish for everything to happen as it actually does happen, and your life will be serene."
— Marcus Aurelius, The Meditations 10.33"Mind and reason are able to move through any thing that opposes, as their nature and their will prescribe."
— Marcus Aurelius, The Meditations 10.14"To Nature, who bestows all things and takes them away, the man who has learnt his lesson and respects himself says: 'Give what is thy good pleasure, take back what is thy good pleasure'; and this he says not boasting himself but only listening to her voice and being of one mind with her."
— Epictetus, Discourses 3.11"1 Whoever thinks any other thing to be good except those things which depend on the will, let him envy, let him desire, let him flatter, let him be perturbed; whoever considers anything else to be evil, let him grieve, let him lament, let him weep, let him be unhappy."
— Marcus Aurelius, The Meditations 4.31"Pass through what is left of life as one who has committed all that is yours, with your whole heart, to the gods, and of men making yourself neither despot nor servant to any."
— Marcus Aurelius, The Meditations 8.20"Nature has designed the ending of each thing, no less than its beginning and its continuance, like one who throws a ball up."
— Marcus Aurelius, The Meditations 2.14"For a man could lose neither past nor future; how can one rob him of what he has not got?"
— Marcus Aurelius, The Meditations 11.13"But I will see to it that I may not be found doing or saying anything that deserves to be despised."
— Marcus Aurelius, The Meditations 8.17"But if in another's, whom do you find fault with?"
— Epictetus, The Enchiridion 1"Some things are under our control, while others are not under our control."
— Marcus Aurelius, The Meditations 8.29"Wipe out impressions by continually saying to yourself: it is in my power now not to allow any wickedness to be in this soul of mine, any appetite or disturbance at all, but seeing what is the character of them all I employ each according to its worth."
— Marcus Aurelius, The Meditations 8.01"Therefore, if you have truly seen where the matter at issue lies, put away the question of what men will think of you and be satisfied if you live the rest of your life, be it more or less, as your nature wills."
— Marcus Aurelius, The Meditations 12.05"Now, if indeed it is so, be certain of this that, if it ought to have been otherwise, the gods would have made it so; for were it just, it would also be possible, and were it accordant with Nature, Nature would have brought it about."
— Marcus Aurelius, The Meditations 9.06"Sufficient are the present judgement that grasps its object, the present social act, the present disposition well satisfied with all that comes to pass from a cause outside the self."
— Marcus Aurelius, The Meditations 8.56"For even though we were brought into the world more than anything else for the sake of one another, still each of our governing selves has its own sovereign right; for otherwise the evil of my neighbour would surely be evil of mine, and that was not God's good pleasure, in order that my unhappiness might not depend on someone other than myself."
— Marcus Aurelius, The Meditations 12.24"These three thoughts keep always ready for use: First, in what you do that your act be not without purpose and not otherwise than Right itself would have done, and that outward circumstances depend either on chance or Providence; but neither is chance to be blamed, nor Providence arraigned."
— Marcus Aurelius, The Meditations 2.11"But they do exist, and they do care for men's lives, and they have put it entirely in a man's power not to fall into real ills; for the rest, if anything were an ill, they would have provided also for this, that it may be in every man's power not to fall into it; (and how could what does not make a man worse make his life worse?) [2] But the nature of the Whole would not have winked at these things either out of ignorance or because (though it knew of them) it had not the power to guard against them or to put them right; neither would it have made so vast an error, from want of power or skill, as to permit good and ill to befall indifferently, both good and bad men equally."
— Epictetus, Discourses 3.17"Remember then always and have in readiness the truth, that this is a law of nature—that the superior has an advantage over the inferior in that in which he is superior—and you will never be vexed."
— Marcus Aurelius, The Meditations 9.29"Act as Nature this moment requires; set about it, if it is granted you, and don't look round to see whether any one will know."
— Seneca, Moral Letters to Lucilius 61"That which is bound to be a necessity if you rebel, is not a necessity if you desire it."
— Marcus Aurelius, The Meditations 8.33"Accept without pride, relinquish without a struggle."
— Marcus Aurelius, The Meditations 7.59"Delve within; within is the fountain of good, and it is always ready to bubble up, if you always delve."
— Epictetus, The Enchiridion 28"If someone handed over your body to any person who met you, you would be vexed; but that you hand over your mind to any person that comes along, so that, if he reviles you, it is disturbed and troubled—are you not ashamed of that?"
— Marcus Aurelius, The Meditations 7.57"Love only what falls to your lot and is destined for you; what is more suited to you than that?"
— Marcus Aurelius, The Meditations 2.05"And so you will, if only you do each act as though it were your last, freed from every random aim, from wilful turning away from the directing Reason, from pretence, self-love and displeasure with what is allotted to you."
— Marcus Aurelius, The Meditations 7.54"Everywhere and continually it is in your power to be reverently content with your present circumstance, to behave to men who are present with you according to right and to handle skilfully the present impression, that nothing you have not mastered may cross the threshold of the mind."
— Epictetus, Discourses 1.30"“Tell me then what things are indifferent?” The things which are independent of the will."
— Epictetus, The Enchiridion 10"In the case of everything that befalls you, remember to turn to yourself and see what faculty you have to deal with it."
— Marcus Aurelius, The Meditations 4.32"But most of all you must run over in mind those whom you yourself have known to be distracted in vain, neglecting to perform what was agreeable to their own constitution, to hold fast to this and to be content with this."
— Epictetus, The Enchiridion 18"But for me every portent is favourable, if I so wish; for whatever be the outcome, it is within my power to derive benefit from it.""
— Marcus Aurelius, The Meditations 11.16"This power is in a man's soul, if he is indifferent to what is indifferent; and he will be so, if he regard every one of these indifferent objects as a whole and in its parts, remembering that none of them creates in us a conception about itself nor even comes to us, but they are motionless, and it is we who create judgements about them and so to speak inscribe them on ourselves; and yet we need not inscribe them and, if we do so unconsciously, we can wipe them off again at once."
— Marcus Aurelius, The Meditations 3.12"Now there is no one who is able to prevent this."
— Marcus Aurelius, The Meditations 9.32"You have the power to strip off many superfluities which trouble you and are wholly in your own judgement; and you will make a large room at once for yourself by embracing in your thought the whole Universe, grasping ever-continuing Time and pondering the rapid change in the parts of each object, how brief the interval from birth to dissolution, and the time before birth a yawning gulf even as the period after dissolution equally boundless."
— Marcus Aurelius, The Meditations 6.50"Remember, too, that you set out with a reservation and were not aiming at the impossible."
— Marcus Aurelius, The Meditations 9.01"But those who wish to follow Nature, being like-minded with her, must be indifferent towards the things to which she is indifferent, for she would not create both were she not indifferent towards both."
— Marcus Aurelius, The Meditations 8.46"For the Universal Nature did not bring to you what you could not bear."
— Epictetus, The Enchiridion 43"Everything has two handles, by one of which it ought to be carried and by the other not."
— Marcus Aurelius, The Meditations 11.36"'There is no robber of the will,' as Epictetus says."
— Marcus Aurelius, The Meditations 10.35"Accordingly the healthy understanding too must be ready for all circumstances; but that which says: 'may my children be kept safe' or 'may all men praise whatever I do', is the eye looking for green or the teeth for what is tender."
— Seneca, On Peace of Mind 1.13"This is why we say that nothing befalls the wise man which he did not expect—we do not make him exempt from the chances of human life, but from its mistakes, nor does everything happen to him as he wished it would, but as he thought it would: now his first thought was that his purpose might meet with some resistance, and the pain of disappointed wishes must affect a man's mind less severely if he has not been at all events confident of success."
— Marcus Aurelius, The Meditations 12.08"Consider the causes of reality stripped of their covering; the relations of your actions; the nature of pain, pleasure, death, fame; who is not the author of his own unrest; how none is hindered by his neighbour; that all things are what we judge them to be."
— Marcus Aurelius, The Meditations 6.41"Should you propose to yourself as good or evil something beyond your will, the necessary result is that, if you fall into that evil or fail of that good, you blame the gods and you hate men who are or who you suspect will be the causes of your loss of the good or your falling into the evil; and indeed we commit many wrongs from concern in regard to these things, If, however, we decide that only what our will controls is good or evil, then no ground is left either to arraign God or to adopt the position of an enemy to man."
— Marcus Aurelius, The Meditations 5.19"Things as such do not touch the soul in the least: they have no avenue to the soul nor can they turn or move it."
— Marcus Aurelius, The Meditations 12.35"For him whose sole good is what is in due season, who counts it all one to render according to right reason more acts or fewer, and to whom it is no matter whether he beholds the world a longer or a shorter time—for him even death has lost its terrors."
— Epictetus, The Enchiridion 19"You can be invincible if you never enter a contest in which victory is not under your control."
— Marcus Aurelius, The Meditations 10.01"Wilt thou rather be satisfied with present circumstance and pleased with all the present, and convince thyself that all is present for thee from the gods and all is well for thee and will be well whatsoever is dear to them to give and whatsoever they purpose to bestow for the sustenance of the perfect living creature, the good and just and beautiful, which begets, sustains, includes, and embraces all things that are being resolved into the generation of others like themselves?"
— Musonius Rufus, Lectures IX"For such a man does not value or despise any place as the cause of his happiness or unhappiness, but he makes the whole matter depend upon himself and considers himself a citizen of the city of God which is made up of men and gods."
— Seneca, On the Shortness of Life 1.05"Cicero called himself “half a prisoner,” but, by Hercules, the wise man never would have come under so lowly a title: he never would be half a prisoner, but would always enjoy complete and entire liberty, being free, in his own power, and greater than all others: for what can be greater than the man who is greater than Fortune?"
The obvious objection is that this is quietism dressed up as wisdom, and the authors themselves are the answer to it. Marcus was the most powerful man alive and Epictetus had been someone's property; neither concluded that nothing was worth doing. The dichotomy is about where you locate your stake, not whether you act. You give the effort fully and let the outcome be what it is. Worth noticing how much of this topic is Marcus. He returns to the same distinction hundreds of times across the Meditations, which tells you something about the idea: it is not one you grasp and keep. It has to be reapplied every time something goes wrong.